However on Wednesday William Hague confirmed that talks had been held, indicating a meeting was on the cards.

"British officials in Washington are in contact with Mr Romney's team regarding his proposed visit to London in July and potential meetings with Members of the Government," the foreign secretary said.

Hague made the comments in a written parliamentary answer to Labour's shadow foreign secretary Douglas Alexander.

In a separate answer Hague said the Olympic Games would be a chance for the government to build relationships with foreign leaders.

"The Olympic and Paralympic games are first and foremost a festival of sport and a celebration of human sporting endeavour," he said.

"But we welcome the opportunity that the games present to demonstrate Britain's qualities to the world and will work to ensure that those that visit us have the best possible experience of their time here. We hope that stronger bilateral relationships will be part of the legacy of the games."

In May the Romney campaign was forced to deny suggestions that several of its senior officials were unhappy with Cameron's recent visit to Washington.